What is the future of humanity and space travel

[spoohunter]

While I admit my fascination with space travel and colonization is a result of endless exposure to science fiction as a child, I think it is a subject that lacks the serious discussion it warrants.

Should the colonization of other worlds be something very much on the political radar? Or is it less important than concepts like ending world hunger and creating world peace?

It is scientifically possible, or will be it be in the near future?

Should we aim to terraform mars? Find a planet somewhere with an earthlike atmosphere and colonize it? If we colonize, how do we keep people alive long enough to get out there?

The only feasible possibility I see besides colonizing say, Mars, is creating huge ecosystems, like space stations, filling them with enough people to function as a society, reproducing as they travel, and send them to other far-a-way planets.

I also think it is incredibly important.

[JoshuaD]

I think we'll have mars and possibly the moon colonized in a realtively short period of time. (No more than 500 years)

I don't think we'll try to colonize other solar systems for a long while. The voyager probes just passed by pluto, and they've still got another 10,000 YEARS to go before they're outside our solar system.

If faster than light travel is impossible, I don't think humans will ever go beyond our solar system.

[A_C_Slater]

I read in National Geographic that Terraforming of Mars is possible (to make Earth-like) by releasing large amounts of Hydrogen into the atmosphere. This will take hundreds of years.

As far as the Voyager probe, if humans did try to tavel to the next solar system they would be traveling much faster than that probe. There is a theoretical design that I've seen in my college astronomy book regarding a ship that could travel about 1/4 light speed.

The ship has a giant plate shaped disc on the the tail end and a theory is that by igniting hundreds of hydrogen bombs directly behind the plate then the explosions will propel the ship at an astronomical speed. I think it was estimated that it would take 40 years to reach Alpha Centauri (a triple star system) at this ship's speed, but there is no gurantee that there's a Terran planet in that solar system. But I figure by that time this will be known.

Also, the ships cost would be about the yearly GNP of the entire planet.

[TimM]

Why the limit on the speed? As long as you have enough fuel, you can keep accelerating forever. The passengers will experience a constant acceleration as long as the "fuel" is "burned" at a constant rate, while those observing would see the acceleration decrease as the ship gets closer to light speed, relative to Earth.

It wouldn't pay to launch a ship that would take 40 years to get to the next nearest star. It would be better to use some of those 40 years to build a faster and cheaper ship.

[A_C_Slater]

Hmmmm... it seems Alpha Centauri is only 4.35 light years away. So it seems that I was wrong about the 1/4 light speed. Maybe it was about 1/10 light speed which would be about 18,600 miles per second. The circumference of the Earth is 24,902 miles.

[TimM]

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The only feasible possibility I see besides colonizing say, Mars, is creating huge ecosystems, like space stations, filling them with enough people to function as a society, reproducing as they travel, and send them to other far-a-way planets.

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This is the so-called "Generation Starship". It would be really hard to know, from here, whether a planet in another system would be uninhabitable for some reason, so you could be hopping around for thousands of years before you find a good planet. I think it would be really tough to keep one of these things going for that long without something going wrong that winds up killing everyone.

[TimM]

Found a very cool site for this stuff:

Orion Project

Project Prometheus

Daedalus Project

Generation ship

[Harv72b]

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is it less important than concepts like ending world hunger and creating world peace?

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I would argue that the colonization of other worlds would go a long way towards solving, or at least alleviating, both of those problems.

A few options I've read about/thought of for getting to these other planets without FTL spaceships:

-Stasis, or some form of artificially induced longterm hibernation. I don't personally think this one will work, as even assuming that science can create a way to keep humans alive in stasis for the decades or centuries required to travel to a suitable planet outside of our solar system (I seem to remember reading that Alpha Centauri is not thought to have any planets at all, let alone terran ones), there are so many other problems which could happen & must be solved. Among them, creating a smart enough AI to pilot the ship, care for the people on board, and wake & care for them when they arrive.

-Genetic manipulation. This one really intrigues me. Basically, the colonists would no longer be [censored] sapiens, technically, but a genetic mutation of our species. Theoretically, you could engineer humans to age slower, live longer, require less food, surivive for long periods of time without gravity...just about anything.

-Cloning. Fairly self-explanatory. You could either equip the ship to conduct cloning during travel, allowing for a relatively small group of colonists, or stock the vessel with "just add water" clones to be created upon arrival by a caretaker crew (or AI, if possible).

-Various interdimensional forms of travel. I.e., "warp speed", folds in space, wormholes, and the like. Technically FTL travel, but theoretically still within the universal speed limit as the ship is technically leaving this universe while "traveling".

-Cyborgs. Just like Battlestar Gallactica, create a "race" of intelligent machines in our image, which could then do the colonizing for us while not having to worry about things like food, water, and molecular aging. While this wouldn't exactly help us should the Earth ever become uninhabitable, it would at least ensure that some form of "humanity" survives.

I think we'll do it eventually (I don't see how our species can continue to survive & multiply at our present rate without colonizing other planets), but I'm not so optimistic to think it'll happen in the next 500 years. At least, not beyond a setup similar to current observation posts in Antarctica (rotating crews, entirely dependent on outside supply).

[Harv72b]

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Why the limit on the speed? As long as you have enough fuel, you can keep accelerating forever.

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This is not thought to be true. As I understand it, most scientists believe that the speed of light is the universal "speed limit". There are theoretical ways around this, which I mentioned in my last post, but I don't believe it's possible to simply "accelerate forever", even in a vacuum. There's also the little matter of various objects which exist in space, and how to avoid them as you get closer and closer to the speed of light.

And then there's the logistical problem. Beyond a certain point, any added acceleration you gained by carrying extra fuel would be offset by the increased thrust required to get the added mass moving. This would be true even if the ship were built in orbit. You would either have to design a ship which was pretty much all fuel (and find enough fuel to fill it), or else come up with some form of propulsion which could refuel itself during travel. Since space is notoriously devoid of things like rocket fuel, this would be difficult to do (though not impossible; I've often wondered about a "space jet" which could collect various subatomic particles traveling freely through space and use them for propulsion, even using light itself as fuel. I think that's a ways off from being practctally possible, though).

[Jake (The Snake)]

I think the interesting question is whether or not we will be able to colonize other planets before we (A) run out of resources on earth, (B) overpopulate, or (C) kill ourselves or become extinct in some way.

(B) can probably be taken care of by population control and genetic manipulation stuff but (A) and (C) could be problems.